What is a cell membrane?
Put in a simplified way, the cell membrane can be considered a skin or a cell barrier of the cell. It keeps all internal components - or cytoplasm - in its cell inside and external items outside its. Its main purpose is to maintain the integrity of the cell and determine what can enter and step out of the cell.
The cell membrane consists of a lipid double -layer. Lipid molecules are formed in two rows, each row is a mirror image of the second row. Two parts form the structure of lipid molecules - hydrophobic and hydrophilic cut. The hydrophobic part avoids molecules similar to water and water and pointing inside the forming center of the lipid double -layer, while the hydrophilic part attracts the molecules similar to water or water and points outwards. It is therefore possible to determine the basis of the mosaic fluid model.
The mosaic of the cell membrane model was discovered in 1972. It describes the arrangement of proteins inside or on the Bilayer RTUID. The proteins are inserted into it in many different ways and create a mosaic of proteins. ProtrudingEiny, which exceeds the lipid double -layer, is important for the transmission of small molecules over the membrane.
Since the cell membrane is semi -permeable, only certain small molecules can pass back and forth through the cell membrane by a process called diffusion. However, the membrane must be permeable or open to a small molecule that tries to cross - similarly to the open door before it can occur - similar to the open door. If the cell membrane is not permeable, it must not go through a small molecule - and the door can be considered closed. In addition, a small molecule can only move from an area that is more crowded to an area that is less crowded. For example, if the amino acid wants to move through the membrane to the cell and the cell membrane is permeable for amino acids, beyond the cells, more amino acids and less amino acids inside the cell must be more amino acid to enter the diffusion cell.
another process to which toIt is scraped through the cell membrane, the transport is facilitated. In some small molecules, proteins found in the cell membrane may also help these molecules through the membrane. It's almost as if the proteins accompany them. Like the diffusion, transport can only be transported if the molecules move from the area of higher concentrations at a lower concentration - or from an area with multiple molecules into an area with a smaller number of molecules.
Finally, the molecules can exceed the cell membrane through an active transport. In active transport, molecules move from areas with lower concentration to higher concentrations - opposite diffusion and facilitated transport processes - against concentration gradient. Energy form adenosine triphosphate (ATP) is required to be against the gradient. ATP can be used for several different cellular activities from movement to reproduction.